diff --git a/crates/g3-core/src/take_screenshot_test.rs b/crates/g3-core/src/take_screenshot_test.rs
new file mode 100644
index 0000000..a90d81e
--- /dev/null
+++ b/crates/g3-core/src/take_screenshot_test.rs
@@ -0,0 +1,37 @@
+// Test to verify take_screenshot requires window_id
+
+#[cfg(test)]
+mod take_screenshot_tests {
+    use super::*;
+    use serde_json::json;
+
+    #[test]
+    fn test_take_screenshot_requires_window_id() {
+        // Create a tool call without window_id
+        let tool_call = ToolCall {
+            tool: "take_screenshot".to_string(),
+            args: json!({
+                "path": "test.png"
+            }),
+        };
+
+        // Verify that window_id is missing
+        assert!(tool_call.args.get("window_id").is_none());
+    }
+
+    #[test]
+    fn test_take_screenshot_with_window_id() {
+        // Create a tool call with window_id
+        let tool_call = ToolCall {
+            tool: "take_screenshot".to_string(),
+            args: json!({
+                "path": "test.png",
+                "window_id": "Safari"
+            }),
+        };
+
+        // Verify that window_id is present
+        assert!(tool_call.args.get("window_id").is_some());
+        assert_eq!(tool_call.args.get("window_id").unwrap().as_str().unwrap(), "Safari");
+    }
+}